1. Field of the Invention
The invention generally relates to interventionless diagnosis of formation characteristics in wells.
2. Description of Related Art
After completion, it may be desirable to diagnose formation characteristics of the well for a number of reasons. For example, the diagnosis may provide a basis for well remediation and treatment, for the case when the well is in the appropriate condition to accept some form of treatment. Furthermore, the analysis may provide a basis for informed placement and construction of subsequent wells.
Diagnosing a well typically requires a “production logging” operation. This operation is an intrusive technique for horizontal wells and usually requires running a tool string on coiled tubing to access the horizontal section of the well. The use of production logging may be undesirable because the logging only provides a snapshot in time. Furthermore, production logging may only be applicable to a subset of the horizontal well population. For example, pumping wells typically cannot be logged unless they have a bypass mechanism; long horizontal wells typically cannot be logged because of coiled tubing access limitations; and subsea wells typically cannot be logged in a cost-effective manner because these wells require intervention vessels.
Thus, there is a continuing need for a noninvasive technique of production logging in wells.